Stringed instrument construction



Aug. 13, 1968 N. M. JOHNSTON 3,396,622

STRINGED INSTRUMENT CONSTRUCTION 2 Sheets-Sheet 1 Filed March 24, 1967 FIG C5 INVENTOR. NORMAN PLJoHNsToN Aug. 13, 1968 N. M. JOHNSTON STRINGED INSTRUMENT CONSTRUCTION 2 Sheets-Sheet 2 Filed March 24 1967 NORMANHJOHNS'IDN Wm i Mg MORLEVS Un te 8w Pa n STRINGED INSTRUMENT CONSTRUCTION Norman M. Johnston, 1305 McPherson Blvd., Fremont, Ohio 43420 Filed Mar. 24,'1967,Ser. No. 625,791 Claims. (Cl. 84318) ABSTRACT OF THE DISCLOSURE A modified construction for stringed instruments, such as a guitar, featuring insets between the fret bars containing an aperture having a recessed spring or clamp element adapted to'releaseably engage a downwardly projecting stud secured to a linear bar having a cushion strip on its underside for depressing the strings of the instrument laterally across the fingerboard.

The present invention relates to stringed instruments generally, and more particularly to a modification in construction of such instruments featuring an integral capo tasto device.

Capo tasto devices, more frequently and more commonly referred to simply as a capo, are well-known devices for clamping the strings of a stringed instrument, such as a guitar, banjo or ukelele, in a particular location to thereby change the keyof the string or strings when plucked by the finger or pick.

Present capo devices on the market are unsatisfactory principally because they are cumbersome and thereby interfere with the normal finger positioning and movement across thefingerboard of the instrument. Some of the capo devicesare unsatisfactory because they are difiicult to locate securely in the proper position and even more difficult to change from one location to another.

The player encounters a further difficulty in that the length of a conventional capo extends beyond the limits of the finger bar laterally, in order to engage the holding structure which passes beneath the neck of the instrument.

It is a principal object of the present invention to provide a construction for stringed instruments which features an integral capo device which is relatively unobtrusive yet extremely functional and very easily manipulated when used by the player of the instrument.

It is also an object of the present invention to provide an integral capo device which is positive in that a device is held snugly against the strings compressing them between the device and the fingerboard, while at the same time is readily releasable and then movable to another position at any time desired by the player.

It is still another object of the present invention to provide a stringed instrument having an integral capo unit which is extremely economical of construction and yet is very strong and durable.

The foregoing and other objects of the present invention will become apparent to those skilled in the art from the following detailed description taken in conjunction with the annexed sheets of drawings on which there is presented, for purposes of illustration only, a single embodiment of the present invention. The invention will be described in connection with a guitar as representative of stringed instruments.

In the drawings:

FIG. 1 is a perspective view of a guitar to which is releasably afiixed a capo tasto device in accordance with the present invention;

FIG. 2 is a broken-away perspective view, greatly enlarged, of a small segment of the fingerboard of the guitar shown in FIG. 1 and particularly showing the integral inset portion of the device;

FIG. 3 is a sectional view taken on the line 33 of FIG. 2;

3,396,622 Patented Aug. 13, 1968 FIG. 4 is an enlarged plan view of the inset device with interior details shown in dotted outline; and

FIG. 5 is a side elevation, partially sectioned, view of the complete device in secured and operative relationship.

The guitar construction of the present invention envisions a fingerboard having a fiush inset between a plurality of the fret bars; said insets having an aperture therein having a recessed releasable engagement means adapted to engage a stud projecting downwardly from a bar member; said bar including a cushion strip on the underside thereof.

Referring now more specifically to the drawings, there is shown in FIG. 1 a guitar 11 composed of a sound box member 12, a centrally located tailpiece 14 and, extending from the sound box, a fingerboard 16 having at its opposite end a keyboard 18; the latter bearing a plurality of keys 20. The strings 21 of the guitar are connected to the bridge or tailpiece 14, extend over the circular hole 13 in the sound box 12 and extend along the fingerboard 16 and are then secured in turn to the six keys which may be rotated to adjust the tension in the strings. The fingerboard includes a plurality of fret bars 23 which span the width of the fingerboard, as more clearly shown in FIG. 2. The fret bars project slightly upwardly and provide a contact point for one or more of the strings as they are depressed by the finger of the player at a point, for example, midway between the frets. In accordance with the present invention, the fingerboard has located between the six fret bars closest to the keyboard an inset 24 Which is, in the manner to be described more fully hereinafter, adapted to releasably engage the capo bar unit 27. Also in accordance with the present invention, one of the insets is located at the extremity of the keyboard, as shown in FIG. 1, for storage of the capo bar 27 when not in use. The inset 24 is mounted so that the upper surface is in flush relationship with the upper surface of the fingerboard.

The upper surface of the fingerboard is usually composed of an ivory or plastic upper facing strip or inlay 26 (FIG. 3). The inset 24, as shown, is generally oval in plan view and includes generally centrally thereof an integral metal enclosure 25 having an upper wall 25a inclusive of a central upper aperture 251;. The central aperture extends into an interior compartment 250 defined by annular side wall 25d and bottom wall 25e. The bottom wall is incomplete in that an inner edge thereof is bent downwardly to form an annular boss 25 which is definitive of a somewhat larger aperture 25g generally in axial alignment with the aperture 25b on the upper side. Inside the compartment 250, there is located a linear spring 25h which is bent into the generally U-shaped configuration shown in dotted outline in FIG. 4. As can be seen, the spring includes, in addition to the U, a pair of spaced sideby-side legs and 81, each having central concave portions identified by the reference numerals 83 and 84. The spring is located so that the concaved or semi-circular region portions 83 and 84 of the legs are generally in registry with the aperture 25b on the upper side of the metal element 25a. A pin or depression 30 serves to hold the spring in proper location as, of course, do the interior walls of the metal compartment 25a which confine or limit the movement of the spring. The opposed concave portions 83 and 84 of the spring are normally urged inwardly toward each other to exert, in effect, a clamping action. However, if subjected to a force, the concave regions can temporarily be pushed apart by reason of the freedom of action afforded by the hooked end portions 25m.

The capo bar member 27 (see FIG. 5) includes an upstanding handle 28 and, on its underside, a cushion strip 29. The capo bar also includes, integrally secured thereto centrally thereof, a downwardly projecting metal stud '32. The stud is generally smoothly dome-shaped at its outer extremity. The dome is necked inwardly, as at 33-, to define a continuous encircling channel between the annular shoulders 35 and 37; the latter forming the base portion of the dome which connects to the underside of the bar. The metallic stud extends upwardly into the bar 27 to hold the two securely together.

The stud 32 is sized to be received by the aperture 25b when directed normally downwardly toward the inset fiush-ly recessed in the fingerboard. As the stud engages the spring 25h, particularly the opposed concave portions 84 and 85, the crowned dome gently forces the end extremities 25m apart and permits the dome end to pass through. As the shoulder 35 passes the spring, the spring will tend to resume its normal closer-together position and will thus exert a spring-like clamping action on the annular channel 33. The purpose of the opposed concavities in the side-by-side leg portions thus become clear.

The stud 32 is not completely domed-shaped, but has two flat sides, as at 40 and 41. The flat sides intersect to define a prow 42. The prow 42 serves to permit the removal of the stud 32 from its spring-held position. Thus, when the finger-manipulated handle 28 is moved in a pivoting action, as indicated by the arrow 45, the prow 42 engages the boss 25 and the entire unit is shifted slightly to the right or toward the sound box, as viewed in FIG. 5. As a consequence of this movement, the channel region 33 contacts the legs 40 and 41 in proximity to their terminal end portions, urging the spring gently apart and allowing, upon continued pivotal movement, the stud channel to disengage itself from the spring and be thusly removed in an easy smooth manner. The faces 40 and 41 provide an escape for the stud channel in sliding by the spring. One or more prows can be formed on the dome, permitting disengagement upon pivotal movement in any one of several directions.

The various parts of the inset, metal enclosure, spring, stud and channel are so designed and dimensioned that when the stud, and particularly the channel portion, is firmly engaged by the spring 25h, the cushion strip will depress the strings 21, as shown in FIG. 5, and hold them in firm contact with the upper surface of the fingerboard. While only one string 21 is shown in FIG. 5, the cushion strip, as can be seen in FIG. 3, extends laterally all the way across the fingerboard and depresses all of the springs simultaneously.

From the foregoing description, it can be seen that the capo member 27 can be located in any one of the five positions shown in FIG. 1 and, as well, at the neutra1 position at the extreme end. The capo device of the present invention is most desirably located in the position shown in the drawings so that the handle is pivoted in the direction of the sound box in order to effect release of the capo bar. This, of course, is not critical and can be changed if desired.

It will be appreciated that a number of clamping arrangements could be employed to give the type of operation herein describe-d. What is essential is that the functioning be smooth, positive and easily releasable. The cushion strip 29 is usually formed of cork but could, of course, be formed of felt, foam, rubber or any similar resilient material. The capo bar 27 can be formed of wood or plastic. Preferably, the inset is plastic and has the metal enclosure securely mounted therein as accomplished by a conventional molding operation. This construction avoids mounting of the metal enclosure directly in the fingerboard which could lead to damage by repeated pivoting action in the disengagement of the stud with the recessed spring. 7

Modifications can be resorted to without departing from the spirit and scope of the present invention as defined in the appended claims.

I claim: t

1. In a stringed instrument comprising a sound box, an attached neck portion,'a--head, a tailpiece mounted on said sound box and a plurality of strings extending between said head and tailpiece across said sound box and along said neckv portion, said neckportion including an upper face bearing a plurality of spaced, transverse, upstanding fret bars against which said strings may be urged to vary the tone or key when plucked; the improvement which comprises:

a plurality of inset members located one between certain of said frets in flush relationship with said upper surface of said neck, said insets including a recessed opening containing releasable engagement means, and

a string-contacting capo member including a bar adapted to extend laterally across said strings, a connectedupstanding handle adapted for finger manipulation, a cushion strip carried on the underside of said bar opposite said handle for contacting said strings and a depending stud adapted for entry into said opening and including means for engaging said recessed engagement means.

2. The improvement as claimed in claim 1, wherein said recessed engagement means is a spring.

3. The improvement as claimed in claim 2, wherein said spring is generally U-shaped with opposed concavities formed on the legs of said U to receive said stud.

4. The improvement as claimed in claim 3, wherein said engagement means on said stud is an annular channel.

5. The improvement as claimed in claim 2, wherein said inset includes a metal enclosure having an upper and lower aperture in registry for receiving said stud, and said spring defines a variable opening in registry with said aperture.

6. The improvement as claimed in claim 3, wherein said stud includes a domed extremity for urging said legs apart.

7. The improvement as claimed in claim 6, wherein said stud includes an undercut channel defining a shoulder for engaging said spring legs.

8. The improvement as claimed in claim 7, wherein said domed extremity is cut away to define two intersecting surfaces defining an escape, permitting. pivotal movement of said stud to release said spring from said undercut channel.

9. The improvement as claimed in claim 5, wherein said enclosure includes a depending boss surrounding said lower aperture.

10. The improvement as claimed in claim 9, wherein said stud includes a U-shaped prow segment adapted to engage said boss on pivotal movement of said handle, thereby urging said stud rearwardly against said concavities urging said legs apart allowing removal of said stud.

No references cited.-

RICHARD B. WILKINSON, Primary Examiner.

CHARLES M. OVERBEY, Assistant Examiner. 

